1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus, which eject liquid droplets from nozzles by the displacement of piezoelectric elements, and an actuator which is provided with a piezoelectric element.
2. Related Art
As a representative example of a liquid ejecting head, an ink jet type recording head which ejects an ink droplet from a nozzle by generating pressure in a pressure generation chamber by a pressure generation section can be given. As the pressure generation section constituting the ink jet type recording head, a piezoelectric element in which a piezoelectric body layer made of a piezoelectric material expressing an electromechanical conversion function is interposed between two electrodes can be given as an example, and the ink droplet is ejected from the nozzle by providing pressure into the pressure generation chamber by flexing and deforming the piezoelectric element.
Also, as for a material of the piezoelectric body layer which is used in the piezoelectric element, for example, a material having a perovskite structure, such as PZT is suitably used. Also, in a case where the piezoelectric body layer is formed of such a material, the piezoelectric body layer is mainly constituted of a crystal of a rhombohedral system or a tetragonal system. For example, there is a piezoelectric element in which the composition Zr/Ti of zirconia and titanium, which are contained in a piezoelectric body layer, is adjusted, and also a crystal thereof is a tetragonal system (for example, refer to JP-A-2005-119166).
In this manner, by adjusting the composition, the crystal system, or the like of the piezoelectric body layer, it is possible to improve a piezoelectric characteristic of the piezoelectric body layer, and therefore, it is possible to improve a displacement characteristic of the piezoelectric element.
However, there is a problem that just with adjustment of the composition or the crystal system of the piezoelectric body layer, there is a limit on improvement in the piezoelectric characteristic, so that a displacement characteristic of the piezoelectric element cannot be sufficiently improved. Also, in recent years, further improvement in displacement characteristic of the piezoelectric element is desired, and it is becoming hard to satisfy the demand.
Also, such a problem exists in not only the piezoelectric element which is used in the ink jet type recording head, but also in a piezoelectric element which is used in a liquid ejecting head which ejects other liquid droplets, and in addition, the problem also exists likewise in an actuator which is used in a device other than the liquid ejecting head.